Ultraviolet lamp connection state detection circuit

Abstract

The invention discloses an ultraviolet lamp connection state detection circuit, and relates to the field of circuit detection, the circuit comprises a driving module, a half-bridge inversion module, an ultraviolet lamp output voltage detection module, a signal amplification module and a control module, the driving module is used for receiving a PWM signal output by the control module and amplifying the PWM signal to obtain a PWM driving signal; the half-bridge inversion module is used for obtaining a stable voltage signal according to the PWM driving signal and supplying power to the ultraviolet lamp through the stable voltage signal; the ultraviolet lamp output voltage detection module is used for outputting an ultraviolet lamp voltage detection signal; the signal amplification module is used for amplifying the ultraviolet lamp voltage detection signal to obtain an ultraviolet lamp voltage detection amplification signal; and the control module is used for judging whether the ultraviolet lamp is successfully connected with the electronic ballast or not according to the change condition of the ultraviolet lamp voltage detection amplification signal in a set time period. According to the invention, timeliness and convenience of detection of the connection state of the ultraviolet lamp and the electronic ballast are improved.

Description

Technical Field

[0001] The present application relates to the field of circuit detection, and in particular to a circuit for detecting the connection status of an ultraviolet lamp. Background Art

[0002] In the field of ballast-driven UV lamp sterilization, once the output terminal of the traditional electronic ballast is disconnected from the wire of the UV lamp, the ballast filament open circuit protection will be triggered, and the electronic ballast will stop working immediately to avoid damage to the ballast. This protection mechanism brings a lot of inconvenience to practical applications, especially in the field of water sterilization. Since the distance between the UV lamp and the output terminal of the ballast is far, the staff needs to connect the filament first, and then re-energize the input power of the ballast to make the system work, which increases the inconvenience of work. Moreover, if the UV lamp does not work after the ballast input is re-energized, it is necessary to run to the farther location of the UV lamp again to re-check the connection between the UV lamp filament line and the output terminal of the ballast, which increases the tediousness of system problem troubleshooting. Summary of the invention

[0003] The purpose of the present application is to provide a UV lamp connection status detection circuit to solve the problems of low timeliness and low convenience in the existing detection of the connection status between the UV lamp and the electronic ballast.

[0004] To achieve the above objectives, this application provides the following solutions:

[0005] The present application provides a UV lamp connection status detection circuit, comprising: a driving module, a half-bridge inverter module, a UV lamp output voltage detection module, a signal amplification module and a control module;

[0006] The driving module is connected to the control module, and is used to receive the PWM signal output by the control module and amplify the PWM signal to obtain a PWM driving signal;

[0007] The half-bridge inverter module is connected to the driving module and the ultraviolet lamp respectively, and the half-bridge inverter module is used to obtain a stable voltage signal according to the PWM driving signal, and to power the ultraviolet lamp through the stable voltage signal;

[0008] The input end of the ultraviolet lamp output voltage detection module is respectively connected to the first end of the second terminal and the first end of the third terminal of the electronic ballast, the first end of the first terminal and the first end of the fourth terminal of the electronic ballast are both connected to the half-bridge inverter module, the second end of the first terminal, the second end of the second terminal, the second end of the third terminal and the second end of the fourth terminal of the electronic ballast are all connected to the ultraviolet lamp, and the ultraviolet lamp output voltage detection module is used to output an ultraviolet lamp voltage detection signal;

[0009] The signal amplification module is connected to the ultraviolet lamp output voltage detection module, and the signal amplification module is used to amplify the ultraviolet lamp voltage detection signal to obtain an ultraviolet lamp voltage detection amplified signal;

[0010] The control module is connected to the signal amplification module, and the control module is used to determine whether the ultraviolet lamp is successfully connected to the electronic ballast according to the change of the ultraviolet lamp voltage detection amplification signal within a set time period.

[0011] Optionally, the control module includes:

[0012] A first ultraviolet lamp connection state detection unit, used for determining that the ultraviolet lamp is not successfully connected to the electronic ballast when the ultraviolet lamp voltage detection amplified signal is a low level signal within a set time period;

[0013] The second ultraviolet lamp connection state detection unit is used to determine that the ultraviolet lamp is successfully connected to the electronic ballast when the ultraviolet lamp voltage detection amplified signal changes from a high level signal to a low level signal within a set time period.

[0014] Optionally, the ultraviolet lamp includes a first filament, a second filament, a third filament and a fourth filament;

[0015] The second end of the first terminal of the electronic ballast is connected to the first filament of the ultraviolet lamp, the second end of the second terminal of the electronic ballast is connected to the second filament of the ultraviolet lamp, the second end of the third terminal of the electronic ballast is connected to the third filament of the ultraviolet lamp, and the second end of the fourth terminal of the electronic ballast is connected to the fourth filament of the ultraviolet lamp.

[0016] Optionally, the driving module includes a first resistor, a second resistor, a half-bridge driver, a first diode, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first capacitor and a first power supply;

[0017] The power pin of the half-bridge driver is connected to the first power supply, the first control signal input pin of the half-bridge driver is connected to the output end of the first resistor, the second control signal input pin of the half-bridge driver is connected to the output end of the second resistor, the ground pin of the half-bridge driver is grounded, the first drive output pin of the half-bridge driver is connected to the input end of the sixth resistor, the second drive output pin of the half-bridge driver is connected to the input end of the fourth resistor, the input end of the first diode is connected to the first power supply, the input end of the third resistor is connected to the output end of the first diode, the drive voltage supply pin of the half-bridge driver is respectively connected to the output end of the third resistor and the input end of the first capacitor, the input end of the fifth resistor is connected to the output end of the fourth resistor, the output end of the fifth resistor is connected to the output end of the first capacitor, the seventh resistor is connected to the output end of the sixth resistor, and the output end of the seventh resistor is grounded.

[0018] Optionally, the half-bridge inverter module includes a second power supply, a first MOS tube, a second MOS tube, a first inductor, a second capacitor and a third capacitor;

[0019] The gate of the first MOS tube is connected to the output end of the fourth resistor, the drain of the first MOS tube is connected to the second power supply, the drain of the second MOS tube is respectively connected to the source of the first MOS tube and the reference potential providing pin of the half-bridge driver, the gate of the second MOS tube is connected to the output end of the sixth resistor, the source of the second MOS tube is grounded, the input end of the first inductor is connected to the output end of the first capacitor, the output end of the first inductor is connected to the input end of the second capacitor, the output end of the second capacitor is connected to the input end of the third capacitor, and the output end of the third capacitor is grounded.

[0020] Optionally, the ultraviolet lamp output voltage detection module includes an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor and a relay;

[0021] The eighth resistor, the ninth resistor, the tenth resistor, the eleventh resistor and the twelfth resistor are connected in sequence and the output end of the twelfth resistor is grounded, the input end of the thirteenth resistor is connected to the output end of the tenth resistor, the input end of the fourteenth resistor is connected to the output end of the thirteenth resistor, the output end of the fourteenth resistor is grounded, the first end of the relay is connected to the third terminal of the electronic ballast, the third end of the relay is connected to the second end of the second terminal of the electronic ballast, and the first end of the relay is connected to the third end of the relay.

[0022] Optionally, the signal amplification module includes a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, a voltage regulator, an eighteenth resistor, a nineteenth resistor, an operational amplifier, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a two-way diode and a third power supply;

[0023] The fifteenth resistor, the seventeenth resistor and the eighteenth resistor are connected in sequence, and the input end of the fifteenth resistor is connected to the output end of the thirteenth resistor, the input end of the sixteenth resistor is connected to the output end of the fifteenth resistor, the output end of the sixteenth resistor is connected to the output end of the voltage regulator, the input end of the voltage regulator is connected to the output end of the seventeenth resistor, and the output end of the voltage regulator is grounded, the first end of the operational amplifier is connected to the output end of the eighteenth resistor, the nineteenth resistor, the twentieth resistor, the twenty-first resistor and the twenty-second resistor are connected in sequence, and the input end of the nineteenth resistor and the output end of the twenty-second resistor are both grounded, the second end of the operational amplifier is connected to the output end of the nineteenth resistor, the third end of the operational amplifier is connected to the input end of the twenty-first resistor, the first end of the two-way diode is grounded, the second end of the third end of the two-way diode is connected to the third power supply, and the third end of the two-way diode is connected to the output end of the twenty-first resistor.

[0024] Optionally, the ultraviolet lamp working voltage collection pin of the control module is connected to the output end of the twenty-first resistor, the first PWM signal output pin of the control module is connected to the first control signal input pin of the half-bridge driver, the second PWM signal output pin of the control module is connected to the second control signal input pin of the half-bridge driver, and the relay drive signal output pin of the control module is connected to the relay.

[0025] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0026] The present application provides a UV lamp connection status detection circuit, which obtains the UV lamp voltage detection signal through the UV lamp output voltage detection module, and judges the connection status of the UV lamp and the electronic ballast according to the UV lamp voltage detection signal through the control module to determine whether the UV lamp is successfully connected to the electronic ballast. There is no need to re-power on the input end of the electronic ballast every time the test is performed. The staff can solve the usage problems on site, which greatly improves the convenience and timeliness of maintenance and detection work. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A circuit diagram of a UV lamp connection status detection circuit in an embodiment of the present application;

[0029] Figure 2 A circuit diagram of a signal amplification module provided in one embodiment of the present application;

[0030] Figure 3 A schematic diagram of the pin structure of a control module provided in one embodiment of the present application;

[0031] Figure 4 A flowchart of software function implementation provided in an embodiment of the present application;

[0032] Reference numerals:

[0033] The first terminal of the electronic ballast is P1, the second terminal of the electronic ballast is P2, the third terminal of the electronic ballast is P3, the fourth terminal of the electronic ballast is P4, the first resistor is R304, the second resistor is R305, the half-bridge driver is U301, the third resistor is R317, the fourth resistor is R302, the fifth resistor is R303, the sixth resistor is R306, the seventh resistor is R308, the first capacitor is C304, the first power supply is H_12V, the first diode is D302, the power supply pin is VCC, the first control signal input pin is HIN, the second control signal input pin is LIN, the ground pin is COM, the drive voltage supply pin is VB, the second drive output pin is HO, the reference potential supply pin is VS, the first drive output pin is LO, the first MOS tube-Q301, second MOS tube-Q302, first inductor-L301A, second capacitor-C303, third capacitor-C305, second power supply-Vdc1, eighth resistor-R5, ninth resistor-R4, tenth resistor-R3, eleventh resistor-R2, twelfth resistor-R1, thirteenth resistor-R7, fourteenth resistor-R6, relay-relay1B, fifteenth resistor-R101, sixteenth resistor-R102, seventeenth resistor-R103, voltage regulator-ZD1, eighteenth resistor-R104, nineteenth resistor-R105, operational amplifier-U1C, twentieth resistor-R106, twenty-first resistor-R107, twenty-second resistor-R109, dual-path diode-D1, lamp-ultraviolet lamp. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0036] In an exemplary embodiment, Figure 1 and Figure 2 As shown, a UV lamp connection status detection circuit is provided, including: a drive module, a half-bridge inverter module, a UV lamp output voltage detection module, a signal amplification module and a control module.

[0037] The driving module is connected to the control module, and is used to receive the PWM signal output by the control module and amplify the PWM signal to obtain a PWM driving signal.

[0038] The half-bridge inverter module is connected to the driving module and the ultraviolet lamp respectively, and is used to obtain a stable voltage signal according to the PWM driving signal, and to power the ultraviolet lamp through the stable voltage signal. The half-bridge inverter module is an LCC half-bridge circuit.

[0039] The input end of the ultraviolet lamp output voltage detection module is respectively connected to the first end of the second terminal P2 of the electronic ballast and the first end of the third terminal, the first end of the first terminal P1 of the electronic ballast and the first end of the fourth terminal are both connected to the half-bridge inverter module, the second end of the first terminal P1 of the electronic ballast, the second end of the second terminal, the second end of the third terminal and the second end of the fourth terminal are all connected to the ultraviolet lamp, and the ultraviolet lamp output voltage detection module is used to output an ultraviolet lamp voltage detection signal. Wherein, the ultraviolet lamp includes a first filament, a second filament, a third filament and a fourth filament; the second end of the first terminal P1 of the electronic ballast is connected to the first filament of the ultraviolet lamp, the second end of the second terminal P2 of the electronic ballast is connected to the second filament of the ultraviolet lamp, the second end of the third terminal P3 of the electronic ballast is connected to the third filament of the ultraviolet lamp, and the second end of the fourth terminal P4 of the electronic ballast is connected to the fourth filament of the ultraviolet lamp.

[0040] The signal amplification module is connected to the ultraviolet lamp output voltage detection module, and the signal amplification module is used to amplify the ultraviolet lamp voltage detection signal to obtain an ultraviolet lamp voltage detection amplified signal.

[0041] The control module is connected to the signal amplification module, and the control module is used to determine whether the ultraviolet lamp is successfully connected to the electronic ballast according to the change of the ultraviolet lamp voltage detection amplification signal within a set time period.

[0042] As an optional implementation, the control module includes: a first ultraviolet lamp connection status detection unit, which is used to determine that the ultraviolet lamp is not successfully connected to the electronic ballast when the ultraviolet lamp voltage detection amplified signal is a low-level signal within a set time period; the first ultraviolet lamp connection status detection unit, which is used to determine that the ultraviolet lamp is successfully connected to the electronic ballast when the ultraviolet lamp voltage detection amplified signal changes from a high-level signal to a low-level signal within a set time period.

[0043] Specifically, Figure 1 and Figure 3As shown in the figure, when the output end of the electronic ballast is not connected to the UV lamp, Figure 3 The first PWM signal output pin (PWMH pin) and the second PWM signal output pin (PWML pin) in the circuit will send out a PWM signal with a frequency of 50KHZ and a duty cycle of 5%. This PWM signal will drive Figure 1 In the LCC half-bridge circuit, the first MOS tube Q301 and the second MOS tube Q302 are complementary turned on, and finally a lower safety voltage, that is, a stable voltage signal, is generated at both ends of the third capacitor C305 to power the ultraviolet lamp.

[0044] When the first filament and the second filament of the UV lamp are not connected to the electronic ballast, Figure 1 The voltage of the UV lamp voltage detection signal V2 is 0, and the UV lamp voltage detection signal V2 will be sent to the signal amplification module. After calculation and processing, it will be converted into the UV lamp voltage detection amplification signal VLAMP_ADC and finally sent to Figure 3 The PA00 pin of the control module MCU in the MCU is connected. When the MCU recognizes that PA00 is at a low level, it is determined that the filament of the ultraviolet lamp is not successfully connected at this time, that is, the filament of the ultraviolet lamp is not completely connected to the terminals of the electronic ballast, and the lighting process is not started at this time.

[0045] like Figure 1 and Figure 3 As shown, if the first filament and the second filament of the ultraviolet lamp are completely connected to the first terminal P1 and the second terminal P2 of the electronic ballast, V2 will generate a high level and be finally detected by the MCU. Then the MCU will perform subsequent logical judgment, that is, whether the third filament and the fourth filament of the ultraviolet lamp are completely connected to the third terminal P3 and the fourth terminal P4 of the electronic ballast. The judgment logic is: the MCU's relay 1B drive signal output pin PA02 will output a high level to close the relay relay1B. If the third filament and the fourth filament of the ultraviolet lamp are also completely connected, then V2 will be forced to be pulled down to GND by the relay relay 1B, the third filament and the fourth filament, and V2 will change from a high level to a low level. The ultraviolet lamp working voltage collection pin VLAMP_ADC will correspondingly change to a low level, and then the MCU's PA00 pin level will change from a high level to a low level. The MCU determines that all the filaments of the ultraviolet lamp are connected at this time, and it will start the preheating and ignition process to start the ultraviolet lamp.

[0046] As an optional implementation, Figure 1As shown, the driving module includes a first resistor R304, a second resistor R305, a half-bridge driver U301, a first diode D302, a third resistor R317, a fourth resistor R302, a fifth resistor R303, a sixth resistor R306, a seventh resistor R308, a first capacitor C304 and a first power supply H_12V.

[0047] The power pin VCC of the half-bridge driver U301 is connected to the first power supply H_12V, the first control signal input pin HIN of the half-bridge driver U301 is connected to the output end of the first resistor R304, the second control signal input pin LIN of the half-bridge driver U301 is connected to the output end of the second resistor R305, the ground pin COM of the half-bridge driver U301 is grounded, the first drive output pin LO of the half-bridge driver U301 is connected to the input end of the sixth resistor R306, the second drive output pin HO of the half-bridge driver U301 is connected to the input end of the fourth resistor R302, The input end of the first diode D302 is connected to the first power supply H_12V, the input end of the third resistor R317 is connected to the output end of the first diode D302, the driving voltage providing pin VB of the half-bridge driver U301 is respectively connected to the output end of the third resistor R317 and the input end of the first capacitor C304, the input end of the fifth resistor R303 is connected to the output end of the fourth resistor R302, the output end of the fifth resistor R303 is connected to the output end of the first capacitor C304, the seventh resistor R308 is connected to the output end of the sixth resistor R306, and the output end of the seventh resistor R308 is grounded.

[0048] As an optional implementation, Figure 1 As shown, the half-bridge inverter module includes a second power supply Vdc1, a first MOS transistor Q301, a second MOS transistor Q302, a first inductor L301A, a second capacitor C303 and a third capacitor C305.

[0049] The gate of the first MOS tube Q301 is connected to the output end of the fourth resistor R302, the drain of the first MOS tube Q301 is connected to the second power supply Vdc1, the drain of the second MOS tube Q302 is respectively connected to the source of the first MOS tube Q301 and the reference potential providing pin VS of the half-bridge driver U301, the gate of the second MOS tube Q302 is connected to the output end of the sixth resistor R306, the source of the second MOS tube Q302 is grounded, the input end of the first inductor L301A is connected to the output end of the first capacitor C304, the output end of the first inductor L301A is connected to the input end of the second capacitor C303, the output end of the second capacitor C303 is connected to the input end of the third capacitor C305, and the output end of the third capacitor C305 is grounded.

[0050] As an optional implementation, Figure 1As shown, the ultraviolet lamp output voltage detection module includes an eighth resistor R5, a ninth resistor R4, a tenth resistor R3, an eleventh resistor R2, a twelfth resistor R1, a thirteenth resistor R7, a fourteenth resistor R6 and a relay 1B.

[0051] The eighth resistor R5, the ninth resistor R4, the tenth resistor R3, the eleventh resistor R2 and the twelfth resistor R1 are connected in sequence and the output end of the twelfth resistor R1 is grounded, the input end of the thirteenth resistor R7 is connected to the output end of the tenth resistor R3, the input end of the fourteenth resistor R6 is connected to the output end of the thirteenth resistor R7, the output end of the fourteenth resistor R6 is grounded, the first end of the relay relay1B is connected to the third terminal of the electronic ballast, the third end of the relay relay 1B is connected to the second end of the second terminal of the electronic ballast, and the first end of the relay relay 1B is connected to the third end of the relay relay 1B.

[0052] As an optional implementation, Figure 2 As shown, the signal amplification module includes a fifteenth resistor R101, a sixteenth resistor R102, a seventeenth resistor R103, a voltage regulator ZD1, an eighteenth resistor R104, a nineteenth resistor R105, an operational amplifier U1C, a twentieth resistor R106, a twenty-first resistor R107, a twenty-second resistor R109, a dual-path diode D1 and a third power supply.

[0053] The fifteenth resistor R101, the seventeenth resistor R103 and the eighteenth resistor R104 are connected in sequence, and the input end of the fifteenth resistor R101 is connected to the output end of the thirteenth resistor R7, the input end of the sixteenth resistor R102 is connected to the output end of the fifteenth resistor R101, the output end of the sixteenth resistor R102 is connected to the output end of the voltage regulator tube ZD1, the input end of the voltage regulator tube ZD1 is connected to the output end of the seventeenth resistor R103, and the output end of the voltage regulator tube ZD1 is grounded, the first end of the operational amplifier U1C is connected to the output end of the eighteenth resistor R104, and the nineteenth resistor R1 05. The twentieth resistor R106, the twenty-first resistor R107 and the twenty-second resistor R109 are connected in sequence, and the input end of the nineteenth resistor R105 and the output end of the twenty-second resistor R109 are both grounded, the second end of the operational amplifier U1C is connected to the output end of the nineteenth resistor R105, the third end of the operational amplifier U1C is connected to the input end of the twenty-first resistor R107, the first end of the two-way diode D1 is grounded, the second end of the third end of the two-way diode D1 is connected to the third power supply, and the third end of the two-way diode D1 is connected to the output end of the twenty-first resistor R107.

[0054] As an optional implementation, Figure 3As shown, the ultraviolet lamp working voltage collection pin of the control module is connected to the output end of the twenty-first resistor R107, the first PWM signal output pin of the control module is connected to the first control signal input pin HIN of the half-bridge driver U301, the second PWM signal output pin of the control module is connected to the second control signal input pin LIN of the half-bridge driver U301, and the relay 1B drive signal output pin of the control module is connected to the relay 1B.

[0055] In an exemplary embodiment, Figure 4 As shown in the figure, the implementation of the software function adopts the impulse area equivalent method and the interpolation operation method, among which, the impulse area equivalent method is specifically: continuously collect the voltage value of the Vlmap_ADC pin 5000 times (that is, the ultraviolet lamp voltage detection amplified signal), and then calculate the average value of the 5000 voltage values. It takes about 200ms to collect 5000 points, and then multiply the average value by 1.414 to get the relatively accurate voltage effective value of the ultraviolet lamp voltage detection amplified signal within 200ms.

[0056] The impulse area equivalent method is divided into 3 steps:

[0057] 1) Data collection: Continuously collect the VLAMP_ADC pin voltage (ultraviolet lamp voltage detection amplification signal) for 5000 times, and sum the VLAMP_ADC pin voltage collected 5000 times to obtain M.

[0058] 2) Calculate the average value: The added VLAMP_ADC pin voltage is averaged to obtain M / 5000=N.

[0059] 3) Calculate the effective value: calculate N*K (K is an effective value coefficient, here K=1.414), get the result obtained by the impulse area equivalent method, assign this result to Vadc (Vadc=N*1.414), and then use the interpolation formula to calculate the actual voltage of the UV lamp.

[0060] Interpolation operation: Calculate the linear corresponding output value based on the input value. The input value is the current and voltage ADC value collected by the MCU, and the output value is the actual working current and voltage. In the MCU, the maximum and minimum values ​​of the input value and the corresponding maximum and minimum values ​​of the output value have been written, so after the MCU collects the current and voltage ADC values, the actual current and voltage values ​​can be obtained by calculation. For example, the maximum ADC value written in the MCU is 1V and the corresponding actual voltage is 100V. Then the ADC collects 0.1V, which corresponds to the actual voltage of 10V, and the same is true for current. The specific interpolation calculation formula is as follows: Vlamp = Vlamp min + ((Vadc-Vadc min) * (Vlamp max-Vlamp min)) / (Vadc max-Vadc min); wherein, Vlamp is the actual lamp voltage of the ultraviolet lamp; Vadc is the collected VLAMP_ADC pin voltage, the effective value calculated by the impulse area equivalent method; Vlamp_min is the preset minimum value of the actual lamp voltage; Vlamp_max is the preset maximum value of the actual lamp voltage; Vadc_min is the preset minimum value of the ADC collected voltage data; Vadc_max is the preset maximum value of the ADC collected voltage data.

[0061] For example: Vadc_min=0V, the corresponding actual UV lamp voltage Vlamp_min is 0V; Vadc_max=3V, the corresponding actual UV lamp voltage Vlam_max is 300V; then when the effective value of Vadc calculated by the impulse area equivalent method is 0.1V, the calculation process of the actual UV lamp voltage Vlamp is as follows:

[0062] Vlamp=0+((0.1-0)*(300-0)) / (3-0)=10V.

[0063] Therefore, when the effective value of the Vadc voltage data calculated by the impulse area equivalent method is 0.1V, it is considered that the actual voltage of the UV lamp is 10V at this time.

[0064] like Figure 4As shown, after the device is powered on, the software will control the MCU to output a PWM pulse signal with a frequency of 50KHZ and a duty cycle of 5% through the PB14 and PB15 pins. This signal will drive the LCC half-bridge circuit, and Q301 and Q302 will be turned on complementary, and finally a lower safety voltage will be generated at both ends of C305. This voltage is the actual voltage in the software. The actual voltage is converted into VLAMP_ADC after the circuit is scaled year-on-year, and finally sent to the PA00 pin of the MCU. The MCU obtains the effective value through the impulse area equivalent method, and then uses interpolation to obtain the corresponding actual working voltage. When the working voltage at this time is less than the preset threshold (20V), it is determined that there is no filament connection, and the lighting process will not be started, and then the heartbeat of 50KHZ and 5% duty cycle will be continuously output. When the working voltage at this time is greater than the preset threshold (20V), it is determined that the first and second filaments of the ultraviolet lamp are fully connected, and then the MCU's PA02 pin outputs a high level to close the second terminal of relay relay1B, and calculates the working voltage again. When the working voltage at this time is greater than the set threshold (20V), it is determined that the third and fourth filaments are not connected, and then the heartbeat is returned. When it is less than the preset threshold, it is determined that the filaments of the ultraviolet lamp are fully connected, and then the preheating and ignition process is started to start the ultraviolet lamp.

[0065] Beneficial effects of this application:

[0066] This application uses a control module to judge the connection status of the ultraviolet lamp and the electronic ballast according to the ultraviolet lamp voltage detection signal, and determines whether the ultraviolet lamp is successfully connected to the electronic ballast, without having to re-power on the input end of the electronic ballast every time it is detected. The staff can solve the usage problems on site, and it also supports remote operation, which greatly improves the convenience and timeliness of maintenance and detection work. The operator can directly replace the ultraviolet lamp tube at a distance from the electronic ballast, and can directly judge whether the ultraviolet lamp is working normally according to the ultraviolet lamp indicator. And when the load ultraviolet lamp is not connected to the output terminal of the electronic ballast, it can be protected in time and remain in standby state to maintain the hot plug of the ultraviolet lamp.

[0067] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0068] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A UV lamp connection status detection circuit, characterized in that: The ultraviolet lamp connection state detection circuit comprises: a driving module, a half-bridge inverter module, an ultraviolet lamp output voltage detection module, a signal amplification module and a control module; The driving module is connected to the control module, and is used to receive the PWM signal output by the control module and amplify the PWM signal to obtain a PWM driving signal; The half-bridge inverter module is connected to the driving module and the ultraviolet lamp respectively, and the half-bridge inverter module is used to obtain a stable voltage signal according to the PWM driving signal, and to power the ultraviolet lamp through the stable voltage signal; The input end of the ultraviolet lamp output voltage detection module is respectively connected to the first end of the second terminal and the first end of the third terminal of the electronic ballast, the first end of the first terminal and the first end of the fourth terminal of the electronic ballast are both connected to the half-bridge inverter module, the second end of the first terminal, the second end of the second terminal, the second end of the third terminal and the second end of the fourth terminal of the electronic ballast are all connected to the ultraviolet lamp, and the ultraviolet lamp output voltage detection module is used to output an ultraviolet lamp voltage detection signal; The signal amplification module is connected to the ultraviolet lamp output voltage detection module, and the signal amplification module is used to amplify the ultraviolet lamp voltage detection signal to obtain an ultraviolet lamp voltage detection amplified signal; The control module is connected to the signal amplification module, and the control module is used to determine whether the ultraviolet lamp is successfully connected to the electronic ballast according to the change of the ultraviolet lamp voltage detection amplification signal within a set time period.

2. The ultraviolet lamp connection status detection circuit according to claim 1, characterized in that: The control module comprises: A first ultraviolet lamp connection state detection unit, used for determining that the ultraviolet lamp is not successfully connected to the electronic ballast when the ultraviolet lamp voltage detection amplified signal is a low level signal within a set time period; The second ultraviolet lamp connection state detection unit is used to determine that the ultraviolet lamp is successfully connected to the electronic ballast when the ultraviolet lamp voltage detection amplified signal changes from a high level signal to a low level signal within a set time period.

3. The ultraviolet lamp connection status detection circuit according to claim 1, characterized in that: The ultraviolet lamp comprises a first filament, a second filament, a third filament and a fourth filament; The second end of the first terminal of the electronic ballast is connected to the first filament of the ultraviolet lamp, the second end of the second terminal of the electronic ballast is connected to the second filament of the ultraviolet lamp, the second end of the third terminal of the electronic ballast is connected to the third filament of the ultraviolet lamp, and the second end of the fourth terminal of the electronic ballast is connected to the fourth filament of the ultraviolet lamp.

4. The ultraviolet lamp connection status detection circuit according to claim 1, characterized in that: The driving module includes a first resistor, a second resistor, a half-bridge driver, a first diode, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first capacitor and a first power supply; The power pin of the half-bridge driver is connected to the first power supply, the first control signal input pin of the half-bridge driver is connected to the output end of the first resistor, the second control signal input pin of the half-bridge driver is connected to the output end of the second resistor, the ground pin of the half-bridge driver is grounded, the first drive output pin of the half-bridge driver is connected to the input end of the sixth resistor, the second drive output pin of the half-bridge driver is connected to the input end of the fourth resistor, the input end of the first diode is connected to the first power supply, the input end of the third resistor is connected to the output end of the first diode, the drive voltage supply pin of the half-bridge driver is respectively connected to the output end of the third resistor and the input end of the first capacitor, the input end of the fifth resistor is connected to the output end of the fourth resistor, the output end of the fifth resistor is connected to the output end of the first capacitor, the seventh resistor is connected to the output end of the sixth resistor, and the output end of the seventh resistor is grounded.

5. The ultraviolet lamp connection status detection circuit according to claim 4, characterized in that: The half-bridge inverter module includes a second power supply, a first MOS tube, a second MOS tube, a first inductor, a second capacitor and a third capacitor; The gate of the first MOS tube is connected to the output end of the fourth resistor, the drain of the first MOS tube is connected to the second power supply, the drain of the second MOS tube is respectively connected to the source of the first MOS tube and the reference potential providing pin of the half-bridge driver, the gate of the second MOS tube is connected to the output end of the sixth resistor, the source of the second MOS tube is grounded, the input end of the first inductor is connected to the output end of the first capacitor, the output end of the first inductor is connected to the input end of the second capacitor, the output end of the second capacitor is connected to the input end of the third capacitor, and the output end of the third capacitor is grounded.

6. The ultraviolet lamp connection status detection circuit according to claim 5, characterized in that: The ultraviolet lamp output voltage detection module includes an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor and a relay; The eighth resistor, the ninth resistor, the tenth resistor, the eleventh resistor and the twelfth resistor are connected in sequence and the output end of the twelfth resistor is grounded, the input end of the thirteenth resistor is connected to the output end of the tenth resistor, the input end of the fourteenth resistor is connected to the output end of the thirteenth resistor, the output end of the fourteenth resistor is grounded, the first end of the relay is connected to the third terminal of the electronic ballast, the third end of the relay is connected to the second end of the second terminal of the electronic ballast, and the first end of the relay is connected to the third end of the relay.

7. The ultraviolet lamp connection status detection circuit according to claim 6, characterized in that: The signal amplification module includes a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, a voltage regulator, an eighteenth resistor, a nineteenth resistor, an operational amplifier, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a two-way diode and a third power supply; The fifteenth resistor, the seventeenth resistor and the eighteenth resistor are connected in sequence, and the input end of the fifteenth resistor is connected to the output end of the thirteenth resistor, the input end of the sixteenth resistor is connected to the output end of the fifteenth resistor, the output end of the sixteenth resistor is connected to the output end of the voltage regulator, the input end of the voltage regulator is connected to the output end of the seventeenth resistor, and the output end of the voltage regulator is grounded, the first end of the operational amplifier is connected to the output end of the eighteenth resistor, the nineteenth resistor, the twentieth resistor, the twenty-first resistor and the twenty-second resistor are connected in sequence, and the input end of the nineteenth resistor and the output end of the twenty-second resistor are both grounded, the second end of the operational amplifier is connected to the output end of the nineteenth resistor, the third end of the operational amplifier is connected to the input end of the twenty-first resistor, the first end of the two-way diode is grounded, the second end of the third end of the two-way diode is connected to the third power supply, and the third end of the two-way diode is connected to the output end of the twenty-first resistor.

8. The ultraviolet lamp connection status detection circuit according to claim 7, characterized in that: The ultraviolet lamp working voltage collection pin of the control module is connected to the output end of the twenty-first resistor, the first PWM signal output pin of the control module is connected to the first control signal input pin of the half-bridge driver, the second PWM signal output pin of the control module is connected to the second control signal input pin of the half-bridge driver, and the relay drive signal output pin of the control module is connected to the relay.

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